Micro Communications Corp was the inventor of the tiny tape cartridge drive that was later used by Exatron for their Stringy Floppy. Their device was also used by California Technology International in their Model 1008-A computer.
Here is an article I found from the September 1976 Dr. Dobb's Journal:
PC CARD HOLDS 60 MEGABYTE REMOVABLE
MAGNETIC STORAGE AT LESS THAN
HALF THE PRICE Of DIGITAL CASSETTES
Micro Communications Corp., 80 Bacon St., Waltham, MA 02154, (617) 899-8111, is manufacturing a tiny tape cartridge
drive, small enough to be mounted on a PC board.
It takes a wee, endless-loop tape cartridge that has a maximum capacity of about half a megabit. The drive will run 3"/second. the tape is capable of 2400 flux-changes /
inch. Thus, usig ratio encoding involving three flux changes per bit, one can obtain 800 BPI, and 2400 baud transfer rates. That would load a 16K byte program in less than a minute.
Little Hidden Gotchas: MCC only manufacturers the drive and cartridges. The buyer must supply power (12v), motor speed control and analog R/W electronics, as
well as the digital Interface. But, the price is right: In 5000-piece quantities (all right, which of you end users is
about to turn into a manufacturer?), the drives run from around $22@ with a 1OO-hour toy motor to $36@ with a 1000-hour Swiss motor. And, certified tape cartridges in
that quantity run $1.80 to $2.20@ depending on length, Incidentally, the cartridges weigh less than a half-ounce apiece. Two can be mailed, First Class, for 13 cents (this month).